Dual-stage mounting system for vibratory compactor drum

Abstract

A dual-stage mounting system having an auxiliary support. A first set of elastomeric mounts connects the vibratory compactor drum to the auxiliary support and a second set of elastomeric mounts interconnect the auxiliary support to the vehicular frame. The dual-stage mounting system reduces by more than 70% the vibration transmitted from the drum to the primary support by a single-stage isolation mounting system thereby extending the life of the vehicle and improving operator comfort.

What is claimed is: 
     
       1. A dual-stage isolation mounting system for a rotary compactor drum used for compacting asphalt and earth, said isolation mounting system being adapted for use in vibrationally isolating a drum from a primary support structure interconnected thereto, said isolation mounting system comprising a) an intermediate support structure forming an auxiliary mass adapted for mounting external to said drum;   b) a first set of elastomeric isolation mounts adapted for interconnection between said drum and said intermediate support structure;   c) a second set of elastomeric isolation mounts adapted for interconnection between said intermediate support structure and said primary support structure; whereby significant vibratory energy is dissipated by deforming said first and second sets of elastomeric isolation mounts in shear minimizing an amount of vibrational energy transmitted from said rotary compactor drum to said primary support structure.   
     
     
       2. The isolation mount of claim 1 wherein said rotary compactor drum is vibrated by rotation of an eccentric weight internally within said drum. 
     
     
       3. The isolation mount of claim 2 wherein said mass of said intermediate support structure is selected to fall in a range of between about 20% and 40% of a mass of said rotary drum. 
     
     
       4. The isolation mount of claim 3 wherein the mass of said intermediate support structure is selected to be about one fourth the mass of said rotary drum. 
     
     
       5. The isolation mount of claim 3 wherein said mass of said intermediate support structure is divided substantially evenly into first and second portions adapted for attachment adjacent first and second ends of said drum, respectively. 
     
     
       6. The isolation mount of claim 5 wherein said first set of said elastomeric pads includes a first group of three pairs of elastomeric mounts adapted for attachment between said first end of said drum and a first end portion of said intermediate support structure, and a second group of six spaced elastomeric mounts adapted for attachment between said second end of said drum and a second end portion of said intermediate support structure. 
     
     
       7. The isolation mount of claim 6 wherein a drive motor forms part of said auxiliary mass and said drive motor rotates said compactor drum through said first group of three pairs of elastomeric mounts. 
     
     
       8. The isolation mount of claim 6 wherein said second set of elastomeric pads includes a third group of two pair of elastomeric mounts on said first end of said drum adapted for attachment between said intermediate support structure and said primary support structure and a fourth group of two pair of elastomeric mounts on said second end of said drum adapted for attachment between said intermediate support structure and said primary support structure. 
     
     
       9. The isolation mount of claim 8, wherein said first set of elastomeric mounts have a spring rate which is no greater than about one half the spring rate of said second set of elastomeric mounts.